Diatomaceous Earth Matrix for Low-Temp SCR Catalyst
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Solution Overview
Problem
Current selective catalytic reduction (SCR) catalysts, particularly those with a copper-promoted small pore crystalline molecular sieve in honeycomb monoliths, exhibit reduced activity at low temperatures for converting oxides of nitrogen in the presence of a reducing agent, such as ammonia.
Innovation Solution
Incorporating diatomaceous earth as a matrix component in an extruded solid honeycomb body with a copper-promoted small pore crystalline molecular sieve catalyst, which contains a maximum ring size of eight tetrahedral atoms, enhances the SCR activity, particularly at temperatures between 200-300°C, by improving the catalyst's performance when compared to catalysts without diatomaceous earth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If diatomaceous earth is added as a matrix component, then selective catalytic reduction activity at low temperatures is improved, but device complexity increases
Solution Approach 1:
The patent applies composite materials by combining diatomaceous earth with copper-promoted small pore crystalline molecular sieve in a honeycomb monolith structure. This composite formulation enhances low-temperature SCR activity (200-300°C) while maintaining structural integrity, directly resolving the technical contradiction between improved catalytic performance and increased material complexity.
2Productivity
If diatomaceous earth is incorporated into the catalyst matrix, then NOx reduction efficiency at low temperatures increases, but manufacturing complexity increases
Solution Approach 1:
The patent modifies the catalyst matrix composition by incorporating diatomaceous earth at specific weight percentages (1-20% based on total catalyst weight) to optimize low-temperature NOx reduction efficiency. This parameter change in composition enables enhanced productivity while managing manufacturing complexity through controlled formulation.
3Reliability
If copper-promoted small pore crystalline molecular sieve is used, then SCR activity is enhanced, but cost increases
Solution Approach 1:
The patent uses diatomaceous earth as an intermediary support material that enhances the performance of copper-promoted small pore crystalline molecular sieve. This intermediary role allows the expensive active catalyst components to be utilized more efficiently, improving SCR activity while potentially reducing the overall quantity of expensive materials required.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The use of diatomaceous earth in the catalyst matrix significantly increases the selective catalytic reduction activity per unit weight of the copper-promoted small pore crystalline molecular sieve, leading to improved NOx reduction efficiency at low temperatures.
Implementation Method 1
a copper-promoted, small pore, crystalline molecular sieve catalyst for converting oxides of nitrogen in the presence of a reducing agent, preferably a nitrogenous reducing agent, e.g. NH3. That is a so-called selective catalytic reduction (SCR) catalyst or NH3-SCR catalyst
Implementation Method 2
by using diatomaceous earth as a constituent of the matrix component in an extruded, solid honeycomb body comprising a copper promoted small pore, crystalline molecular sieve catalyst, the selective catalytic reduction activity of the catalyst is improved, particularly at relatively low temperatures (e.g. 200-300° C.)
Data Source
AI summary
An extruded, solid honeycomb body comprises a copper-promoted, small pore, crystalline molecular sieve catalyst for converting oxides of nitrogen in the presence of a reducing agent, wherein the crystalline molecular sieve contains a maximum ring size of eight tetrahedral atoms, which extruded, solid honeycomb body comprising: 20-50% by weight matrix component comprising diatomaceous earth, wherein 2-20 weight % of the extruded, solid honeycomb body is diatomaceous earth; 80-50% by weight of the small pore, crystalline molecular sieve ion-exchanged with copper; and 0-10% by weight of inorganic fibres.